Heat shock proteins (HSPs) (also known as stress proteins or molecular chaperones) are an evolutionarily conserved and diverse group of molecular chaperones that are upregulated in response to cellular stressors such as oxidative stress, glucose deprivation, hyperthermia, hypothermia, infection, inflammation, dehydration, ischemia, and exposure to toxins.
HSPs may be broadly classified into five families according to their molecular mass: HSP100, HSP90, HSP70, HSP60, and small HSPs (sHSPs). sHSPs are known to be abundant in cardiac and skeletal muscle, where they increase in response to stress to protect against muscle ischemia.
The chaperone activities of HSPs include prevention of protein misfolding, refolding of denatured proteins, and targeting of proteins for proteolytic degradation. In humans. HSPs are most notably associated with the cardiovascular, renal, central nervous, lymphatic, and immune systems. In addition, there is a strong functional relationship between the sympathetic nervous system (SNS) and HSPs.
HSPs play a key role in cell survival through cytoprotective mechanisms (Almeida Biomed Pharmacother 65:239 (2011)), and are involved in responding to a variety of disease processes including those of cancer, cardiovascular disease, neurodegenerative disease, trauma, diabetes, and chronic inflammation.